Field of the Invention
The invention relates to a method for a deterministic selection of a sensor from a plurality of sensors.
Description of the Background Art
A method for a deterministic selection of a sensor from a plurality of sensors is known from U.S. Pat. No. 8,519,819 B2. To this end, multiple sensors are connected parallel to one another at a three-wire bus and connected to a control unit. The control unit communicates in accordance with a so-called SENT “Single Edge Nibble Transmission” protocol with the sensors. In order to exchange data with a single sensor, initially a deterministic selection of the sensors is performed by means of the control unit. To this end, the length of time of a pulse is varied by the control unit, i.e. the duration between a falling edge and an edge rising immediately thereafter. In accordance with the method specified here, as well as in general, the rate of rise of the rising edge is only poorly defined in SENT due to the external resistance and conduction capacity used. This can lead to misinterpretations of the duration between the falling and the rising edge. Consequently, an incorrect sensor could be selected.
Further known from U.S. Pat. No. 8,183,982 B2 and U.S. Pat. No. 8,577,634 B2 are sensors connected to a control unit with the use of a three-wire bus.